Rebels in India's north-eastern state of Tripura are making pornographic films to raise money for their separatist campaign, officials say.

The information has come from surrendered guerrillas of the National Liberation Front of Tripura (NLFT), according to police.

They say the rebels are forcing captured tribal women, and some men, to take part in the films.

The films are then dubbed to be sold in India and neighbouring countries.

Remote areas

The former guerrillas of the NLFT have told police their leaders not only sexually abused scores of tribal girls recruited into the rebel army but also used them - and some male guerrillas - to produce scores of porn films, officials say.

"The films were found to be dubbed in Burmese, Bengali, Thai and Hindi, suggesting they were being marketed to many countries in the region," said Ghanshyam Murari Srivastava, Tripura's police chief.

He said police have recovered scores of pornographic DVDs featuring young women and men from various parts of the state, including remote areas such as Amarpur and Gandacherra.

Such pornographic DVDs have also been recovered from NLFT bases inside Bangladesh after they were raided by the Bangladesh army, the police chief said.

'Sleek product'

Discreet inquiries with video production houses in Tripura confirmed what the surrendered rebels are reported to have said.

"We do get orders to process raw porn shot in remote tribal areas from time to time," the owner of a video production company in the state's capital Agartala told the BBC.

He did not want to be named.

Production houses say rebels give them good money for their work

"We get a lot more money , much above our normal rates, to process these films and deliver a sleek final product.

"We know the insurgents are behind these films. When we process their raw stock, we can see boys standing around with automatic rifles and revolvers pulling in girls but we are supposed to cut all that out and just concentrate on the sex," the owner said.

"It is very good money and we don't think it is right to question the insurgents anyway," he said.

The latest pornographic video that has become sought after by young men in Tripura is Hamjagoi Tongthoklaima, or Our Experiences.

Like a feature film, it runs a full cast of "heroes" and "heroines".

Initially it appears to be a love film with boys and girls holding hands and walking past lakes and trees. But soon the video starts featuring close-up shots of the actors undressing and sex.

'Actress fled'

Surrendered NLFT rebels say their leaders have always abused tribal women , both in the villages and also those recruited into the rebel army.

A study by two researchers, Meenakshi Sen Bandopadhyay and Jayanta Bhattacharya, documented in detail sexual abuses perpetrated by the NLFT.

"The NLFT rebels did not allow a tribal girl in North Tripura to get married because they wanted to enjoy her by turns. Her parents were helpless because they lived in a tea garden in a remote area," the study says.

One surrendered NLFT guerrilla Mohan Reang said: "One tribal actress Anita Reang who played the heroine in some local films had to flee her village because a top NLFT leader wanted to whisk her away."

But while forcing tribal women to have sex with them at gunpoint or carrying them away to the rebel camps is not new, using them to produce pornography certainly is.

"This seems to have started a year or two back," says local journalist Manas Paul who began legal proceedings to bring this to the notice of the authorities.

"But it is now rampant, so many of these discs are circulating all over our state and possibly in other parts of northeast India as well," he said.

But in some other northeast Indian states like Manipur, the rebels punish those who produce pornography.

In the state of Manipur, some girls who acted in porn films were shot in the legs, as were the producers.